Data report: a brittle (normal?) shear zone from Hole C0002P: deformation structures and their relationship with calcite veins (IODP Expedition 348, Nankai Trough accretionary prism)

Abstract

A brittle shear zone was sampled from Hole C0002P in the Nankai accretionary prism during Integrated Ocean Drilling Program Expedition 348. Macro- and microscopic structures observed both in the core and the covered petrographic thin sections of this fault zone permit characterization of the deformation during faulting. The observed kinematic indicators are coherent with an apparent normal fault sense with respect to its present-day position. Calcite veins are restricted to the most damaged interval of the cored fault. Descriptions of the vein geometry and relationship with the cataclastic foliation present in the fault suggest that these are extension veins that opened during a crack-seal. The various generations of veins suggest that a reiterative history of brecciation and veining took place.